Abstract

We conduct molecular dynamics simulations of a molecular linear motor consisting of coaxial carbon nanotubes with a long outer carbon nanotube confining and guiding the motion of an inner short, capsulelike nanotube. The simulations indicate that the motion of the capsule can be controlled by thermophoretic forces induced by thermal gradients. The simulations find large terminal velocities of 100–400 nm/ns for imposed thermal gradients in the range of 1–3 K/nm. Moreover, the results indicate that the thermophoretic force is velocity dependent and its magnitude decreases for increasing velocity.

Received 18 September 2009Accepted 08 December 2009Published online 29 December 2009Publisher error corrected 05 January 2010

Acknowledgments:

Support for this work is provided in part by the Danish Research Council (Grant no. 274-06-0465), and the Myhrwold, and Otto Mønsted Foundations. The authors wish to acknowledge discussion with Petros Koumoutsakos and Dimos Poulikakos and computational support from the Danish Center for Scientific Computing (DCSC).

Abstract

We conduct molecular dynamics simulations of a molecular linear motor consisting of coaxial carbon nanotubes with a long outer carbon nanotube confining and guiding the motion of an inner short, capsulelike nanotube. The simulations indicate that the motion of the capsule can be controlled by thermophoretic forces induced by thermal gradients. The simulations find large terminal velocities of 100–400 nm/ns for imposed thermal gradients in the range of 1–3 K/nm. Moreover, the results indicate that the thermophoretic force is velocity dependent and its magnitude decreases for increasing velocity.